Tuesday, May 21, 2013

New paper finds biodiversity was greatest during Roman & Current Warming Periods

A paper published today in The Holocene examines biodiversity in Romania over the Holocene [the past 11,500 years] and finds the periods with the greatest biodiversity were during the Roman Warm Period 2000 years ago, and over the past 500 years during the current warming period. Once again, the data demonstrates warming is beneficial to plant and animal life. According to the authors, "Most distinct episodes of enhanced floristic richness are evident during the Roman Period (2000 cal. yr before the present), and over the last 500 calendar years before the present."Prior posts on biodiversity

Abstract

An understanding of contemporary and likely future biodiversity requires knowledge of how past human societies have shaped diversity patterns. Here, we use long-term pollen data sets extending from lowlands to subalpine environment in the Carpathian region (Romania) with the aim of exploring the relationship between landscape openness, anthropogenic disturbance, elevation and vegetation richness over the Holocene. We found that landscape openness represents a significant driver of pollen richness: The more open sites from mid (440–750 m) and high elevations (1550–1850 m) showed on average greater diversity than more forested upland sites (1050–1360 m). For the first time, our results show pollen richness patterns along elevation gradients that remain constant over the Holocene. Although significant only over the last 3000 cal. yr BP, these elevational patterns become accentuated with stronger evidence of anthropogenic impact. We also found a strong link between diversity change and major land use strategies of prehistoric societies, demonstrating the potential of pollen richness to be used as a tool to depict the ecological impact of human disturbance on diversity. Most distinct episodes of enhanced floristic richness are evident during the Roman Period (2000 cal. yr BP), and over the last 500 cal. yr BP. Recent anthropogenic activity negatively impacted diversity in mountainous areas mainly through plantations; the lack of sites in agriculture landscapes however limits our inference for this type of setting. The maintenance of habitat diversity is key to maintaining high levels of diversity. While there is temporal consistency in the diversity pattern in records from similar climate and vegetation settings, comparison of diversity from different vegetation assemblages and levels landscapes openness should be interpreted cautiously.